Field of the Invention
The present invention relates to an inkjet printing apparatus.
Description of the Related Art
Japanese Patent Application Laid-Open No. 2006-35685 discusses an inkjet printing apparatus which can perform borderless printing. A platen for supporting a sheet has a plurality of ink guide grooves formed by a large number of ribs which are arranged along a conveyance direction of the sheet. An ink absorber is arranged downstream of the ink guide grooves. Excess ink that is discharged toward and impinges on the platen during borderless printing is guided by the ink guide grooves which are slightly tilted, and is absorbed by the ink absorber provided on the platen.
In the printing apparatus discussed in the foregoing Japanese Patent Application Laid-Open No. 2006-35685, the ink absorber provided on the platen is arranged in a narrow space below the ribs on the downstream side. Since the ink absorber has a small capacity, if the printing apparatus is used for a long period of time, the ink absorber becomes unable to absorb ink any more. Then, ink accumulates on the platen. If such ink accumulates in large amounts, the ink overflows from the platen and drips into the interior of the printing apparatus, whereby the interior of the printing apparatus is contaminated.
If the printing apparatus discussed in the foregoing Japanese Patent Application Laid-Open No. 2006-35685 is installed on a non-horizontal, tilted installation surface, a problem similar to the one described above can occur depending on the angle and direction of the tilt. More specifically, if the tilt of the installation surface cancels out the tilt of the platen and the platen is on a horizontal line, the ink which has impinged on the platen does not flow but accumulates in the ink guide grooves. If the tilt of the installation surface is greater, the ink in the ink guide grooves flows not toward the absorber (to a downstream side) but backward (to an upstream side) by gravity. If such ink flows backward in large amounts, the ink drips off from the platen to contaminate the interior of the printing apparatus.
If a sheet passes over the ink accumulated on the platen as described above, the ink adheres to the back of the sheet to cause a stain on the sheet. Further, if the accumulated ink drips into the interior of the printing apparatus, since the printing apparatus is structurally difficult to clean, the liquid component of the ink can cause problems such as erosion of component parts and a short circuit in electrical parts.